Pediatric germ cell tumors

P B, Ramadwar M, Singh S, Shukla A, Panwala H, Sahu A, Siddharth L, Kapadia T. Imaging Recommendations for Diagnosis, Staging, and Management of Pediatric Solid Tumors

Paediatric extra-cranial solid tumours are one of the common causes for paediatric malignancies. Lack of appropriate imaging at presentation, staging and for follow-up is a major challenge for paediatric solid tumours. We have reviewed the paediatric solid tumour imaging protocols suggested by the major oncological societies/groups around the world (mainly the SIOP – Society International Pediatric Oncology, and the COG – Children's Oncology Group). We have adapted some of those protocols to develop imaging recommendations for the diagnosis, staging and management of extra-cranial solid tumours based on the treatment protocols followed in India.

Expression of BARD1 β Isoform in Selected Pediatric Tumors

Currently, many new possible biomarkers and mechanisms are being searched and tested to analyse pathobiology of pediatric tumours for the development of new treatments. One such candidate molecular factor is BARD1 (BRCA1 Associated RING Domain 1)—a tumour-suppressing gene involved in cell cycle control and genome stability, engaged in several types of adult-type tumours. The data on BARD1 significance in childhood cancer is limited. This study determines the expression level of BARD1 and its isoform beta (β) in three different histogenetic groups of pediatric cancer—neuroblastic tumours, and for the first time in chosen germ cell tumours (GCT), and rhabdomyosarcoma (RMS), using the qPCR method. We found higher expression of beta isoform in tumour compared to healthy tissue with no such changes concerning BARD1 full-length. Additionally, differences in expression of BARD1 β between histological types of neuroblastic tumours were observed, with higher levels in ganglioneuroblastoma and ganglioneuroma. Furthermore, a higher expression of BARD1 β characterized yolk sac tumours (GCT type) and RMS when comparing with non-neoplastic tissue. These tumours also showed a high expression of the TERT (Telomerase Reverse Transcriptase) gene. In two RMS cases we found deep decrease of BARD1 β in post-chemotherapy samples. This work supports the oncogenicity of the beta isoform in pediatric tumours, as well as demonstrates the differences in its expression depending on the histological type of neoplasm, and the level of maturation in neuroblastic tumours.

Klinefelter syndrome and germ cell tumors: review of the literature

Objective

The most common presentation of Klinefelter syndrome (KS) is infertility and features of hypogonadism. Currently no consensus exists on the risk of malignancy in this syndrome. Several case reports show an incidence of extragonadal germ cells tumors (eGCT) of 1.5 per 1000 KS patients (OR 50 against healthy population). Malignant germ cell tumors are rare in children. They account for 3% of all children cancers. Young patients with a germ cell tumor are not routinely tested for Klinefelter syndrome. This can therefore result in underdiagnosing. Literature data suggest a correlation between eGCT and KS. To the best of our knowledge there is no precise description of the primary locations of germ cell tumors in KS patients. The purpose of this study is to evaluate age groups and primary locations of extragonadal germ cell tumors in Klinefelter patients. With this data we investigate whether it is necessary to perform a cytogenetic analysis for KS in every eGCT patient.

Study design

This study is based on case report publications in PubMed/Medline published until march 2020 that described "Klinefelter Syndrome (MeSH) AND/OR extragonadal germ cell tumors". Publications were included when patients age, location and histology of the germ cell tumor was known. Two double blinded reviewers selected the studies.Results: 141 KS patients with eGCTs were identified. Mean age at presentation was 17.3 years (StDev + - 10.2). In contrast to the extragonadal germ cell tumors in adults, most eGCT in children were mediastinal or in the central nervous system (respectively 90/141; 64% and 23/141; 16% of all tumors). Distribution of histologic subtypes showed that the largest fraction represented a teratoma, mixed-type-non-seminomateus GCT and germinoma, respectively 34/141; 24%, 26/141; 18% and 20/141; 14% of all tumors.

Conclusion

These data suggest a correlation between primary extragonadal germ cell tumors and Klinefelter syndrome. There appears to be an indication for screening on KS in young patients with an eGCT in the mediastinum. A low threshold for radiologic examinations should be considered to discover eGCT. We emphasize the need for genetic analysis in all cases of a male with a mediastinal germ cell tumor for the underdiagnosed Klinefelter syndrome.

Mature Ovarian Teratoma: Atypical Imaging

The incidence of a mature ovarian teratoma ranged from 20% to 30% of pediatric ovarian tumors (Sabaa et al., 2009), which is composed of well-differentiated tissues that derive from all three germ cell layers (ectoderm, mesoderm, and endoderm); it is one of the most common benign ovarian neoplasms. In this case report, we discuss a 9-year-old female patient who presented with abdominal pain and distended abdomen, for which she had an abdominal ultrasound and magnetic resonance imaging. The histopathological exam, after a laparotomy, showed a mature ovarian teratoma.

Comparative genomic analysis of intracranial germ cell tumors - the preliminary study focused on Sonic Hedgehog signaling pathway

Aim of the study

Examination of copy number changes in a group of intracranial germ cell tumors (GCTs) with particular focus on putative aberrations of the main genes coding SHh pathway proteins.

Material and methods

The study was performed on DNA isolated from fresh-frozen tumor tissue samples from eight GCTs, including six intracranial GCTs. The intracranial group consisted of three germinomas, two mature teratomas and one mixed germ cell tumor. Comparative genomic profiling analysis was carried out using microarray-CGH method (Cytosure ISCA UPD 4×180k, OGT). The results were analyzed with Feature Extraction (Agilent Technologies) and Nexus Copy Number (BioDiscovery) softwares.

Results and conclusions

Chromosomal aberrations were found in two intracranial germinomas. These tumors were characterized by complex genomic profiles encompassing chromosomes 7, 8, 9, 10, 11, 12, 16, 17 and 19. Common findings were gain at 12p13.33p11.1 of 35 Mbp and gain at 17q11.1q25.3 of 55 Mbp. In one tumor, also SHh (7q36.3), SMO (7q32.1) and GLI3 (7p14.1) copy gains occurred together with 9q21.11q34.3 loss, including PTCH1, all being elements of SHh signaling pathway. Moreover, both tumors showed various copy gain of genes being ligands, regulators, receptors or target genes of SHh (MTSS1; PRKACA and FKBP8) as well as gain of genes of SHh coopting WNT pathway (WNT3, WNT5B, WNT9B in both tumors; WNT16, WNT2 in pineal lesion). Further studies on larger group are needed to characterize SHh-related gene alterations in intracranial GCTs and for searching genotype-phenotype relations.

Epidemiologic study of 230 cases of testicular/paratesticular tumors or masses: 15-year experience of a single center

PURPOSE

This study retrospectively investigated the cases of testicular tumors/masses treated in our center from 2002 to 2017 and analyzed their epidemiologic features.

METHODS

Data were collected by searching our center's database using "testicular tumor" or "testicular mass" as keywords. Patients not operated in our hospital were excluded. Preoperative serum alpha-fetoprotein (AFP) levels were reviewed in germ cell tumor (GCT) cases and analyzed to predict malignancy in various age groups.

RESULTS

In total, 230 cases were identified: 151 were benign (78 in the left, 72 in the right, and 1 bilateral) with 3.63years mean age during the operation, and 79 were malignant (42 in the left, 36 in the right, and 1 bilateral) with 2.21years mean age during the operation. Main pathological diagnoses were mature teratoma (92, 40.00%), yolk sac tumor (53, 23.04%), dermoid cyst (23, 10.00%), embryonic carcinoma (15, 6.53%), immature teratoma (14, 6.09%), benign cyst (8, 3.48%), Leydig cell tumor (6, 2.61%), and paratesticular rhabdomyosarcoma (5, 2.17%). All GCT cases with AFP >1000ng/ml, >100ng/ml, >20ng/ml were malignant in <7-, 7-9-, and ≥10-month-old groups, respectively.

CONCLUSIONS

Radical inguinal orchiectomy without biopsy is suggested in 7-9- and ≥10-month-old cases with AFP >100ng/ml and >20ng/ml, respectively.

TYPE OF STUDY

Retrospective Study.

LEVEL OF EVIDENCE

Level III-IV.

Pure Primary Extragonadal Retroperitoneal Yolk Sac Tumour in a Young Child: A Case Report

Germ Cell Tumours (GCTs) in children are uncommon, constituting approximately only 3% of all malignancies in children younger than 15 years of age. Primary extragonadal GCTs constitute only 1-5% of all GCTs and a retroperitoneal site is seen only in 4% of all extragonadal GCTs. Extragonadal GCTs arise from local transformation of primordial germ cells which have been misplaced during the migration of these cells through the midline dorsal mesentery in the fourth-sixth week of embryogenesis. GCTs in children show remarkable variability in age, site, presentation and histology. This is the case of a three-year-old male child who presented with a history of an abdominal swelling which was rapidly progressive in nature. Radiology showed a large retroperitoneal mass and lesions in the liver. Histopathology, immunohistochemistry and serum Alpha-fetoprotein (AFP) values confirmed a diagnosis of pure primary extragonadal yolk sac tumour.

Epidemiological study of paediatric germ cell tumours revealed the incidence and distribution that was expected, but a low mortality rate

AIM

Germ cell tumours (GCTs) are a rare heterogeneous tumour group derived from primordial germ cells, which can be benign or malignant and occur in the gonads or extragonadally. This study mapped the paediatric GCTs in Denmark from 1984 to 2013 to study the incidence and outcome.

METHODS

We identified paediatric GCTs from the Danish Childhood Cancer and National Pathology Registries and reviewed the case records for patient characteristics, tumour characteristics and clinical outcome.

RESULTS

We identified 403 (71% female) paediatric GCTs and the crude incidence was 1.43 per 100 000. Of these, 79 (20%) were malignant, 39 (10%) were potentially malignant and 285 (70%) were benign. Extragonadal GCTs (39%) were mainly observed in early childhood and were predominately sacrococcygeal teratomas. Gonadal GCTs (61%) in late childhood were most frequently mature teratomas in the ovaries. Nearly all patients underwent surgery. Of the malignant tumours, 62% were treated with chemotherapy. Radiotherapy was only administered to intracranial GCTs. In the cohort, 12 patients died (3%).

CONCLUSION

Paediatric GCTs in Denmark were mainly benign and mortality was low, even for malignant tumours. We identified a peak of extragonadal GCTs in early childhood and a peak of gonadal GCTs in late childhood, which was comparable to previous reports.

Mediastinal teratoma in a neonate with acute respiratory failure

Background: While teratomas account for the leading cause of germ cell tumors, the mediastinal teratomas represent one of the infrequent types of congenital germ cell tumors. Neonates with large mediastinal teratomas generally show severe respiratory distress, and the immediate surgical treatment is needed to alleviate their problems.

Objectives: Report clinical symptoms, diagnostic procedures, treatment option, and outcomes after the treatment for a neonate with a large mediastinal teratoma.

Methods: A 2-day-old female infant presented with acute respiratory failure diagnosed as mediastinal teratoma. It was followed with surgical treatment. The removed tissues were examined pathologically.

Results: The girl suffered an acute respiratory failure two days after birth. The chest radiography, echocardiography, and chest computerized tomography results showed the considerable size of the mediastinal teratoma. A median sternotomy was performed on the third day of infant life to remove the tumor without rupturing the capsule. Pathological diagnosis was germ cell tumor. Clinical follow-ups reported no complication.

Conclusion: The successful management of a neonate with large mediastinal teratomas was presented. Immediate detection and proper treatment of the large mediastinal teratoma in a neonate was most important to decrease the morbidity and mortality of the infant.

Germ cell tumors in atypical locations: experience of the TGM 95 SFCE trial

The yolk sac tumor is one of the most common malignant germ cell tumors in young children and typically occurs in the gonads. We report 6 cases of children less than 30 months old with extragonadal atypical locations of yolk sac tumor. These rare diagnoses were established by raised serum α-fetoprotein levels and biopsies. These patients were treated according to the French TGM 95 trial. All the patients are alive disease-free after ≥2.5 years of follow-up. We want to highlight the importance of measuring the α-fetoprotein levels in very young children presenting with any midline tumor, even if the tumor is not located in the typical extragonadal sites such as the sacrococcyx, mediastinum, retroperitoneum, or vagina.

Recent advances in understanding the etiology and pathogenesis of pediatric germ cell tumors

Pediatric germ cell tumors (GCTs) are rare neoplasms arising predominantly in the gonads and sacrococcygeal, mediastinal, and intracranial localizations. In this article, we review current knowledge of pathogenesis of pediatric GCTs, which differs from adult/adolescent GCTs. One distinctive feature is the absence of a progenitor stage, such as carcinoma in situ or gonadoblastoma, which are seen in adult/adolescent GCTs, except spermatocytic seminoma. The primordial germ cell (PGC) is the suggested origin of all GCTs, with variations in histology reflecting differentiation stage. Expression of pluripotency transcription factors OCT-3/4, NANOG, and AP-2γ in germinomas/seminomas/dysgerminomas is consistent with retaining a germ cell phenotype. Teratomas, in contrast, develop through a pathway of aberrant somatic differentiation of immature germ cells, and the yolk sac tumors and choriocarcinomas result from abnormal extraembryonic differentiation. In pediatric GCTs, origin is suggested at an earlier developmental stage because of predisposing genetic factors, although responsible genes remain largely unknown. Some extragonadal GCTs have been linked to overexpression of the KIT/KITLG system, allowing for survival of aberrantly migrated ectopic PGCs. Infant gonadal/sacrococcygeal GCTs may be caused by apoptosis-related pathways, consistent with an association with polymorphisms in BAK1. Although recent advances have identified candidate pathways, further effort is needed to answer central questions of pathogenesis of these fascinating tumors.

Adult asymptomatic hamartoma in the distal esophagus: a rare case

An esophageal hamartoma is a rare, benign germ-cell condition. Most hamartomas are intraluminal tumors located in the upper third of the esophagus. We herein report an unusual case of a pedunculated hamartoma that involved the lower third of the esophagus that was diagnosed incidentally during investigations for epigastric pain. The features noted on endoscopy, endoscopic ultrasound/Doppler endoscopic ultrasound and computed tomography of the chest are also presented.

DNA methylation in germ cell tumour aetiology: current understanding and outstanding questions

Germ cell tumours (GCTs) are a diverse group of neoplasms that can be histologically subclassified as either seminomatous or non-seminomatous. These two subtypes have distinct levels of differentiation and clinical characteristics, the non-seminomatous tumours being associated with poorer prognosis. In this article, we review how different patterns of aberrant DNA methylation relate to these subtypes. Aberrant DNA methylation is a hallmark of all human cancers, but particular subsets of cancers show unusually high frequencies of promoter region hypermethylation. Such a 'methylator phenotype' has been described in non-seminomatous tumours. We discuss the possible cause of distinct methylation profiles in GCTs and the potential of DNA methylation to provide new targets for therapy. We also consider how recent developments in our understanding of this epigenetic modification and the development of genome-wide technologies are shedding new light on the role of DNA methylation in cancer aetiology.

Prognosis of malignant sacrococcygeal germ cell tumours according to their natural history and surgical management

INTRODUCTION

Malignant sacrococcygeal (SC) germ cell tumours (GCT) may be diagnosed as primary pelvic tumour or malignant recurrence of foetal SC teratoma (FSCT) operated during the neonatal period. In order to evaluate the difference between these two populations, the authors report their experience with SC-GCT registered in the French TGM 95 protocol.

POPULATION AND METHODS

The protocol comprised risk-adapted-chemotherapy (CT) followed by surgery. Standard risk (SR: localized tumour completely resected) had no adjuvant therapy. Intermediate-Risk (IR: localized tumour, incomplete or no initial surgery with αFP<15,000 ng/ml) received Vinblastine-Bleomycin-Cisplatin regimen; while High-Risk (HR: αFP > 15,000 ng/ml and/or metastases) received Etoposide-Ifosfamide-Cisplatin.

RESULTS

Fifty-seven patients with SC-GCT, aged 0-80 months (median 16), were registered between 1995 and 2005. Nineteen patients had secondary SC-GCT after FSCT. All patients received CT: 17 IR and 1 SR after reevolution; 39 HR (25 with metastases). 51 patients underwent delayed surgery, which was incomplete in 8 patients.

EVOLUTION

Seventy-two percent of the secondary SC-GCT had systematic biological follow-up. αFP increasing was the first presenting sign in 80% of the cases. Patients with secondary SC-GCT had a lower median αFP level at diagnosis, were less frequently classified as HR and received less CT. The two groups with secondary vs. primary SC-GCT had a statistically similar favourable outcome (Overall Survival: 93.8% vs. 86.2%; Event-Free Survival: 89.2 vs. 78.2%; p > 0.34 and >0.32), respectively, but with less burden of therapy.

CONCLUSIONS

SC-GCT has a good overall prognosis provided complete surgery is achieved and CT is administered to IR and HR patients. SC-GCT in patients followed by αFP after treatment for FSCT had less tumour extension than newly-diagnosed patients, probably because of earlier detection of the disease.

Anesthetic considerations for the pediatric oncology patient--part 2: systems-based approach to anesthesia

One of the prices paid for chemo- and radiotherapy of cancer in children is damage to the vulnerable and developing healthy tissues of the body. Such damage can exist clinically or subclinically and can become apparent during active antineoplastic treatment or during remission decades later. Furthermore, effects of the tumor itself can significantly impact the physiologic state of the child. The anesthesiologist who cares for children with cancer or for survivors of childhood cancer should understand what effects cancer and its therapy can have on various organ systems. In part two of this three-part review, we review the anesthetic issues associated with childhood cancer. Specifically, this review presents a systems-based approach to the impact from both tumor and its treatment in children, followed by a discussion of the relevant anesthetic considerations.

Imaging of Ovarian Teratomas in Children: A 9-Year Review

Objective

Germ cell tumours are the most common ovarian neoplasms in childhood and, of these, teratomas, whether mature or immature, are the most frequently found. Mature teratoma is a benign tumour, whereas the immature type, although also benign, has a more aggressive course, with a propensity to recurrence. A review of the literature revealed that there are some imaging features that may help to differentiate between these 2 types of teratoma, although no systematic comparison has been made. The objective of this study was to review imaging features of ovarian teratomas in children and to assess differentiating imaging features between the mature and immature types of ovarian teratoma.

Methods

Retrospective analysis of all patients who presented to our institution during a 9-year period (September 1999 to August 2008) with ovarian teratoma as confirmed on histology.

Results

Forty-one patients with pathologically proven ovarian teratoma were found. The patient ages ranged from 4–18 years at presentation (mean [standard deviation] age, 12.4 ± 3.4 years; median age, 13 years). Thirty patients (73.2%) were found to have mature ovarian teratoma, and 11 (26.8%) had immature teratoma. A component of endodermal sinus tumour was found in one of the immature teratomas. On ultrasonography, the appearance of the immature teratomas was purely solid in 3 (27.3%), mixed solid and cystic in 6 (54.5%), and predominantly cystic in 2 (18%). The mature ovarian teratomas demonstrated a predominantly cystic appearance in 22 (73.3%) and a mixed solid and cystic appearance in 8 (26.6%); there were no cases with a pure solid appearance. The prevalence of the more cystic appearance of the mature type showed significant statistical difference when compared with its prevalence in the immature type ( P = .0008, χ2 test). Other imaging features, such as size, presence of fat, or calcifications, did not show a significant difference between the 2 types of teratoma.

Conclusions

The predominance of a cystic component and a pure solid component in ovarian teratoma are significant differentiating factors between the mature type and the more aggressive immature type of teratoma.

Mature gastric teratoma: recurrence in adulthood

A case of mature gastric teratoma developing recurrence after 2 decades after complete excision during infancy is being reported. The patient was successfully managed by surgical resection. Pathologic examination confirmed it to be a mature teratoma.